Glow lamp



Nov. 30, 1954 M. NAzzl-:wsKl 2,695,970

GLOW LAMP Filed Feb. 11, 1953 INVENTOR. MATHEW NAZ ZEWSKE IS TTORNE 5Unit 2,695,970 GLOW LAMP Mathew Nazzewski, Adams, Mass., assignor toSprague Electric Company, North Adams, Mass., a corporation ofMassachusetts Application February 11, 1953, Serial No. 336,278 3Claims. (Cl. S13-117) to being expensive, suffer from inherent opticaldisad- .f

vantages. The prior art lamps used with such systems are, as a rule,characterized by less response to voltage changes than are desired.

It is an object of the present invention to provide a glow or aeo lampswhich can be used in sound recording without an extremely complex lenssystem. A further object is to produce a lamp of the indicated categorywhich can be easily and cheaply manufactured, and which produces a slitof light of uniform intensity, and which is extremely sensitive tovoltage changes. other objects of the invention, as well as theadvantages of it, will be apparent from this description and claims, asthe accompanying drawing, in which:

Figure 1 is a partially sectional front view of a glow lamp inaccordance with the invention; and

Figure 2 is a sectional View of the lamp of Figure 1 taken at line 2 2of Figure 1.

Briefly, the glow lamp of the invention consists of two parallel flatsheet-like electrodes spaced close to one another and a slit-like shieldpositioned from said electrodes so as to restrict the light emitted fromthe area between them, the entire assembly being disposed in a sealedglass tube containing an ionizable gas such as neon, argon, or the like.

The invention will be best understood with reference to the accompanyingdrawings, especially Figure 1. Here it is seen that the preferred lampof the invention consists of a glass envelop sealed at 11 so as tocontain an ionizable gas 21. The preferred gas for use with theinvention is argon, although other equivalent gas known to the art maybe used with satisfactory results. The gas 21 is retained Within theenvelop 10 under pressure. In general, the higher the pressure the moresensitive the voltage response of the lamp. For optimum results basedupon practical and theoretical considerations it is presently consideredthat the pressure should be between about 2 and about 4 atmospheres.

The actual light emission results from the application or voltagebetween two flat parallel electrodes 17. Each of these electrodes isplaced upon an insulating sheet 18 of mica or the like, and is held inposition by bent-over portions 19. By virtue of this construction theelectrodes 17 are free to expand in a crosswise direction when heatedwithout bulking. The bent-over portions 19 preferably extend for thelength of the electrodes 17, and are positioned loosely within notchesin the support members 18 so as to be able to expand lengthwise. Theseelectrodes 17 are attached as by soldering to leads 13 sealed within theenvelopes 10 at 12.

The light emitted between the electrodes 17 is restricted in area to alarge extent by thespacing of these elements. In general, the distancebetween these electrodes 17 is from 1/32 to 1A inch, although this isnot critical. This light is also restricted by two L-shaped memberspositioned so as to define a slit 16 extending substantially the lengthof the electrodes 17 and facing the space between these electrodes sothat light emitted from this area will pass through it. The L members 15are preferably formed of a dark metal so as to cut down the chances ofthe reflection of unwanted radiation.

Both the L members 15 and the electrodes 17 can These and States Patentbe positioned With respect to one another by known means. One highlysatisfactory method comprises attaching these elements to inert micadisks 14 by notching, these disks fitting closely within the walls ofthe envelope. ln the particular construction shown the wire leads 13 aidin hlolding the assembled members 14, 15, 17 and 18 in p ace.

Obviously, the glow lamp shown can be varied widely in construction.Instead of using separate shielding members 15 to define a slit aunitary construction can be used for the same purpose, or the insidewalls of the glass envelope can be coated so as to define a slit facingthe eiectrodes. Reiiective coatings or separate reflectors can be placedopposed from the slit used so as to concentrate light upon this slit,although such elements are not as a rule to be considered necessary ordesirable because they frequently tend to produce a slightly divergentemitted light beam.

The actual voltage used to generate this light, the amount with whichthe emitted beam is concentrated by a lens system which need onlyconsist of a single lens, as well as other factors affecting theconstruction and operation of the new glow lamp are items which are bestdetermined depending upon the specific application involved. Thoseskilled in the art will have a minimum of diiculty with suchdeterminations. For optimum results the slit employed should be placedin close proximity with the electrodes, and the width of the electrodesshould be at least ten times the width of the slit. Further, this slitshould be at most 3%; as wide as the distance between the electrodes foroptimum results.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope hereof, it is to beunderstood that the invention is not limited to the specific embodimentshereof except as defined in the appended claims.

What is claimed is:

1. A glow lamp comprising a sealed glass envelope, au ionizable gascontained within said envelope, insulating disk positioned within and atopposed ends of said envelope, two inert metal L-shaped memberssupported by said disk within said envelope, two parallel rectangularplate electrodes partially disposed between said I -shaped members andsupported by said disk, said insulating disk positioned perpendicular tothe axial planes of said electrodes and said member, said L-shapedmembers defining a focussing slit positioned parallel to said electrodesin such a manner that a plane parallel to said electrodes and disposedtherebetween will pass through said slit and wire leads extending fromsaid electrodes through said glass envelope.

2. A glow lamp comprising two parallel rectangular plate electrodes, twoinert metal L-shaped members disposed about said electrodes, saidmembers defining a slit uniplanar with the volume defined by anddisposed between said parallel electrodes, two electricallynon-conducting supporting disks positioned at the opposed ends of saidelectrodes and said members, a sealed glass envelope disposed about saidelectrodes, said members and said disks, an ionizable gas containedwithin said envelope and wire leads extending from said electrodesthrough said envelope.

3. A glow lamp comprising two parallel rectangular plate electrodes, asealed glass envelope disposed about said electrodes, electricallynon-conducting supports for said electrodes within said envelope, anionizable gas contained within said envelope, wire leads extending fromsaid electrodes through said envelope, and opaque means within saidenvelope constructed and arranged to substantially encompass saidelectrodes but defining a slit uniplanar with the volume defined by anddisposed between said parallel electrodes.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,850,467 Nakken Mar. 22, 1932 1,864,547 Morton et al. June28, 1932 1,879,472 Pirani Sept. 27, 1932 2,111,231 Von Arndenne Mar. l5,1938

